Power management device and method for a consumer product are provided. The power management device includes a memory, a configuration channel interface circuit and a control circuit. When a power supply device is electrically connected to a connector of the consumer product, the control circuit performs a power delivery protocol conforming to a USB specification on the power supply device through the configuration channel interface circuit and a configuration channel pin of the connector, so as to determine a power mode in which the power supply device supplies power to the consumer product. After the power delivery protocol is performed successfully, based on at least one protocol profile stored in the memory, the control circuit performs a vendor-defined messaging protocol on the power supply device through the configuration channel interface circuit and the configuration channel pin, so as to determine whether to change the power mode.